Quick and safe: why a k-wire-extension-block-fixation of a bony mallet finger is the favoured treatment.

INTRODUCTION: Mallet fingers are the most common tendon injuries of the hand. Bony avulsion distal finger extensor tendon ruptures causing a mallet finger require special attention and management. In this monocentral study, we analyzed the clinical and individual outcomes succeeding minimal invasive k-wire extension block treatment of bony mallet fingers. MATERIALS AND METHODS: In a retrospective study, we sent a self-designed template and a QUICK-DASH score questionnaire to all patients, who were treated because of a bony mallet finger between 2009 and 2022 and fulfilled the inclusion criteria. A total of 244 requests were sent out. 72 (29.5%) patients participated in the study. Forty-five men and twenty-seven women were included. RESULTS: 98.7% (n = 75) of the cases were successfully treated. Patients were highly satisfied with the treatment (median 8.0; SD ± 2.9; range 1.0-10.0). Based on the QUICK-DASH score, all patients showed no difficulties in daily life. The extent of avulsion did not influence the outcome. CONCLUSION: We conclude that the minimally invasive treatment of a bony mallet finger should be offered to every patient, because it is safe, fast, and reliable. Thus, we propose to perform extension-block pinning independently of the articular area.

Activated memory B cells may function as antigen-presenting cells in the joints of children with juvenile idiopathic arthritis.

OBJECTIVE: B cells impact the perpetuation of chronic inflammatory or autoimmune diseases in multiple ways. A role of B cells as antigen-presenting cells (APCs) in the pathogenesis of chronic arthritis in humans has been suggested; however, as of yet the presence of such B cells at the site of inflammation has not been demonstrated. This study was undertaken to investigate whether synovial B cells in patients with juvenile idiopathic arthritis (JIA) might display features of APCs. METHODS: The frequency, phenotype, and immunoglobulin repertoire of synovial B cells were studied by flow cytometry and single-cell polymerase chain reaction (PCR). Cytokine expression by B cells was analyzed by real-time PCR, and interaction between B cells and T cells was investigated in a mixed lymphocyte culture. RESULTS: CD27+IgD- and CD27-IgD- B cells accumulated in the joints of JIA patients and displayed an activated phenotype. Both B cell subsets expressed hypermutated and class-switched immunoglobulins, indicators of memory B cells. The accumulating memory B cells expressed the costimulatory molecules CD80/CD86 and showed a higher capacity to activate allogeneic T cells and prime a Th1 phenotype than their peripheral blood counterparts. CONCLUSION: Activated immunoglobulin class-switched CD27- and CD27+ memory B cells, indicating a phenotype of APCs with expression of costimulatory molecules, accumulate in the joints of patients with JIA and might be involved in the amplification of pathogenic T cell activation. These findings provide evidence that B cells play an antibody-independent immunopathologic role in human chronic inflammatory arthritis of childhood.